Add DNA circuit coverage tests

Co-authored-by: quantumdynamics927-dotcom <247722560+quantumdynamics927-dotcom@users.noreply.github.com>
Agent-Logs-Url: https://github.com/quantumdynamics927-dotcom/QPyth/sessions/428f0007-0052-4ed8-bde2-e3cf330ab687

Author: Copilot

tests/test_dna_circuits.py

@@ -5,14 +5,17 @@
 
 import pytest
 
+import quantumpytho.modules.dna_circuits as dna_circuits
 from quantumpytho.modules.dna_circuits import (
     get_available_dna_circuit_ids,
     get_available_dna_circuits,
     get_available_dna_sequences,
     get_dna_circuit_preview,
     get_dna_sequence,
     load_dna_circuit,
+    load_dna_circuit_metadata,
     load_qasm_circuit_file,
+    run_dna_circuit_explorer,
     summarize_dna_circuit,
     validate_qasm_file,
 )
@@ -43,6 +46,14 @@ def test_load_dna_circuit_parses_qasm():
     assert circuit.num_clbits == 21
 
 
+def test_load_dna_circuit_metadata_reads_bundled_json():
+    """Bundled metadata should be readable without summary normalization."""
+    metadata = load_dna_circuit_metadata("dna_helix_10bp")
+
+    assert metadata["qubits"] == 21
+    assert metadata["config"]["base_pairs"] == 10
+
+
 def test_load_stealth_dna_circuit_parses_qasm():
     """Bundled 34bp stealth QASM should parse into a large Qiskit circuit."""
     circuit = load_dna_circuit("stealth_dna_34bp")
@@ -64,6 +75,16 @@ def test_summarize_dna_circuit_normalizes_metadata():
     assert summary.sequences["strand1"] == "GTAGGTAAGC"
 
 
+def test_dna_summary_to_dict_is_json_safe():
+    """Normalized summaries should serialize into simple Python data."""
+    summary = summarize_dna_circuit("dna_helix_10bp")
+    payload = summary.to_dict()
+
+    assert payload["circuit_id"] == "dna_helix_10bp"
+    assert payload["sequences"] == summary.sequences
+    assert payload["geometry"] == summary.geometry
+
+
 def test_summarize_stealth_dna_circuit_preserves_large_asset_metadata():
     """Large stealth asset should preserve curated metadata and parsed metrics."""
     summary = summarize_dna_circuit("stealth_dna_34bp")
@@ -95,6 +116,21 @@ def test_stealth_circuit_preview_contains_named_registers():
     assert "qreg bridge[34];" in preview
 
 
+def test_validate_qasm_file_rejects_missing_file(tmp_path: Path):
+    """Missing QASM files should raise a helpful error."""
+    with pytest.raises(FileNotFoundError, match="not found"):
+        validate_qasm_file(tmp_path / "missing.qasm")
+
+
+def test_validate_qasm_file_rejects_invalid_header(tmp_path: Path):
+    """Non-OpenQASM files should be rejected before parsing."""
+    invalid_qasm = tmp_path / "invalid.qasm"
+    invalid_qasm.write_text("qreg q[1];", encoding="utf-8")
+
+    with pytest.raises(ValueError, match="not valid OpenQASM"):
+        validate_qasm_file(invalid_qasm)
+
+
 def test_validate_qasm_file_rejects_empty_file(tmp_path: Path):
     """Empty QASM placeholders should be rejected clearly."""
     empty_qasm = tmp_path / "empty.qasm"
@@ -113,6 +149,12 @@ def test_available_dna_sequences_contains_blueprint_and_library_entries():
     assert "lib_acgt" in record_ids
 
 
+def test_get_dna_sequence_unknown_record_raises_keyerror():
+    """Sequence lookup should fail clearly for unknown ids."""
+    with pytest.raises(KeyError, match="Unknown DNA sequence record"):
+        get_dna_sequence("missing-record")
+
+
 def test_get_dna_sequence_blueprint_is_normalized():
     """Blueprint sequence should be normalized by stripping separators."""
     record = get_dna_sequence("seq_3")
@@ -122,6 +164,41 @@ def test_get_dna_sequence_blueprint_is_normalized():
     assert record.phi_scaling == pytest.approx(0.7232610426788172)
 
 
+def test_dna_sequence_to_dict_is_json_safe():
+    """Sequence records should serialize into simple Python data."""
+    record = get_dna_sequence("seq_3")
+    payload = record.to_dict()
+
+    assert payload["record_id"] == "seq_3"
+    assert payload["sequence"] == record.sequence
+    assert payload["metadata"] == record.metadata
+
+
+def test_load_dna_circuit_metadata_raises_for_missing_bundled_file(
+    monkeypatch: pytest.MonkeyPatch, tmp_path: Path
+):
+    """Missing bundled metadata files should raise a clear error."""
+    monkeypatch.setattr(dna_circuits, "_data_dir", lambda: tmp_path)
+
+    with pytest.raises(FileNotFoundError, match="DNA metadata file not found"):
+        load_dna_circuit_metadata("dna_helix_10bp")
+
+
+def test_load_dna_circuit_rejects_unknown_asset():
+    """Unknown bundled circuit ids should fail clearly."""
+    with pytest.raises(KeyError, match="Unknown DNA circuit asset"):
+        load_dna_circuit("missing-circuit")
+
+
+def test_load_qasm_circuit_file_rejects_unsupported_openqasm_version(tmp_path: Path):
+    """Unknown OpenQASM versions should fail before import."""
+    qasm_path = tmp_path / "sample.qasm"
+    qasm_path.write_text("OPENQASM 4.0;\nqubit q;\n", encoding="utf-8")
+
+    with pytest.raises(ValueError, match="Unsupported OpenQASM version"):
+        load_qasm_circuit_file(qasm_path)
+
+
 def test_load_qasm_circuit_file_handles_openqasm3_optional_dependency(tmp_path: Path):
     """OpenQASM 3 loading should either parse or fail with an install hint."""
     qasm3_path = tmp_path / "sample.qasm"
@@ -136,3 +213,31 @@ def test_load_qasm_circuit_file_handles_openqasm3_optional_dependency(tmp_path:
     else:
         circuit = load_qasm_circuit_file(qasm3_path)
         assert circuit.num_qubits == 1
+
+
+def test_run_dna_circuit_explorer_allows_quit(
+    monkeypatch: pytest.MonkeyPatch, capsys: pytest.CaptureFixture[str]
+):
+    """CLI explorer should return cleanly when the user quits."""
+    monkeypatch.setattr("builtins.input", lambda _: "q")
+
+    run_dna_circuit_explorer()
+
+    output = capsys.readouterr().out
+    assert "[DNA-Inspired Circuit Explorer]" in output
+    assert "Returning to main menu..." in output
+
+
+def test_run_dna_circuit_explorer_uses_default_selection(
+    monkeypatch: pytest.MonkeyPatch, capsys: pytest.CaptureFixture[str]
+):
+    """Blank input should select the first bundled DNA circuit."""
+    monkeypatch.setattr("builtins.input", lambda _: "")
+    monkeypatch.setattr(dna_circuits.importlib.util, "find_spec", lambda _: None)
+
+    run_dna_circuit_explorer()
+
+    output = capsys.readouterr().out
+    assert "OpenQASM 3 import support: install qiskit_qasm3_import" in output
+    assert "Name: DNA Helix 10bp" in output
+    assert "QASM preview:" in output